Electric-arc lamp.



No. 67!,5I2. Patented Apr. 9, I91. T. E. DROHAN.

ELECTRIC ABC LAMP.

(Application filed June 12, 1900.)

(No Model.)

UNITED STATES PATENT CEEICE.

THOMAS E. DROHAN, OF CHICAGO, ILLINOIS.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 671,512, dated April 9, 1901.

Application filed June 12,1900.

To all whom, it may concern.-

Be it known that I, THOMAS E. DROHAN, a citizen of the United States, residing at Chi cago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Arc-Lamps, (Case No. 1,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

Myinvention relates to arc-lamps either of the constant-current or constant-potential type and operating through the agency of either direct or alternating current, and has for its object the provision of an improved form of clutching means whereby the carbons of the lamp may be relatively fed and controlled without having the feeding and controlling thereof injuriously modified by imperfection either in the workmanship of the lamp or shape of the carbon.

There are many objections to the many wellknown forms of clutches heretofore used that mechanically engage the carbons or carbonholders. Among these objections may be mentioned irregularity in the size of the carbon, imperfection in the construction of the clutches and the carbon-holders, liability of dust working between the clutch and the carbon or carbon-holder engaged thereby, variation in the resistance due to variation in contact between the clutches and the carbons or holders, and the frictional Wear to which the engaging parts are subject.

To overcome the objection due to variation in resistance due to the variation in intimacy of contact between the clutch and the rod or carbon engaged thereby, it has been proposed to use hollow rods, within which the upper carbons are disposed, and to connect flexible conductors directly with the upper ends of the carbons in the hollow rods.

In the preferred embodiment of my invention I dispense with the tubes and the flexible conductors contained within the tubes. In the preferred embodiment of my invention I am also enabled to complete the lamp-circuit Without passing the current through the separable parts of the clutching mechanism.

My invention may be said to comprise a magnetic clutch for controlling the feeding action of the carbon or carbons, the clutch Serial No. 20,006. -Non1odcl.)

having two members, which by their engagement serve to prevent feeding and which permit feeding upon their disengagement.

Generally speaking,the principal feature of my invention in its preferred embodiment may be described as comprising an electromagnetic clutch member that serves to feed or permit the feeding of a carbon, a body of magnetic material being employed which is magnetically attracted to the said electromagnetic clutch member when energized, so that the feeding of the carbon is prevented, the construction being such that when said electromagnetic clutch memberis sufficiently deenergized upon an increase in resistance at the arc the said magnetic attraction will cease momentarily, permitting a feeding of the carbon. In addition to this electromagnetic clutch mechanism I preferably employ a regulating-magnet, which serves to separate the carbons in starting the lamp and to maintain them in separated relation, this regulating-magnet being preferably employed to 0p erate switching mechanism to deenergize the electromagnetic clutch member when the carbon is to be fed and to reenergize the said electromagnetic clutch member when the carbon has been properly fed to prevent a 0011- tinuation of the feeding.

In the preferred embodimentof the invention I preferably shunt the winding of the electromagnetic clutch member when the carbon is to be fed, as I find that the said clutch member is thereby instantaneously sufficiently deenergized to secure an instantaneous feeding.

I will explain my invention more particularly by reference to the accompanying drawings, illustrating the preferred embodiment thereof as employed in constant potential direct-current lamps.

Figure 1 is a side elevation of a lamp of this class constructed in accordance with the invention, the circuit arrangement thereof being diagrammaticallyindicated. Fig. 2 is a sectional view on line 2 2 of Fig. 1. Fig. 3 is a plan view of the electromagnetic clutch.

Like parts are indicated by similar characters of reference throughout the different figures.

I have indicated a source of direct current a in circuit with mains b b. A circuit-closing switch a is included in a bridge of the mains with the lamp. The upper carbon d and the lower carbon 6 are included in this bridge, the helix of the regulating-magnet f, which is preferably iron-clad, being also in eluded in circuit with the said carbons and with a choke or resistance-coil g Which is provided for adjusting the potential at the are of the lamp. The connection between the upper carbon (Z and the helix of the magnet or solenoid f is secured by means of a conductor h, which is preferably flexible in part, one end of the conductor terminating in a binding-screw Z, that constitutes one of the terminals of the helix of magnet f, the other terminal of the conductor it being attached to the carbon-holder 7a, which contains the uppercarbon. The helix of a clutching-electromagnetZ is included in the conductor h. The magnet Z is preferably provided with two clutching-poles m m, each of which is preferably provided with a groove a, which receives a magnetizable bar 0, that may be of iron or steel. Then the lamp is out of service or when the upper carbon is to be fed, the bar 0 is in electrical contact with an abutment or contact 13 in electrical connection with the terminal a. The bar 0 by reason of its contact with the poles m m is also in electrical connection with the carbon-carrier 7c and the upper carbon d. The holder 7t, which in this instance is fixedly secured to the magnet Z, constitutes one of several means that may be employed whereby one of the carbons can be held from feeding when the niagnetizable material is engaged or locked by the said magnet. The helix of the clutching-magnet Z is short-circnited, the short circuit including the bar 0, the upper carbon, and its carrier. 711611 the carbons are separated, the upper carbon is lowered in the feeding, preferably through the agency of the weight of the electromagnet Z, that is preferably mounted upon the carbon-carrier, the magnet Z being sufiiciently deenergized to permit the feeding. The upper end of the bar 0 may be provided with a slot to receive the shorter end of a lever q, pivotally mounted upon a support 0', carried upon the upper head of the magnetf. The leverg in this instance is united by means of a link 3 with the core t of the regulating-solenoid, said solenoid serving when the arc of the lamp is of normal resistance to elevate the bar 0 through the agency of the lever q, and thereby separate the bar 0 from contact 1) to open the short circuit about the magnet Z to prevent the upper carbon from being fed. When the resistance of the are increases, however, the strength of the magnet f will be decreased, whereupon the combined weight of the upper carbon, the magnet Z, carried thereby, and the bar 0 will cause the said bar to descend into engagement with the contact 1), thereby momentarily establishing a short circuit about the winding of the clutch member and per mitting the upper carbon to be fed. The carbons havingbeen brought closer together, the strength of the magnet f is restored and the bar 0 is elevated, whereupon the short circuit is broken and the magnetic attraction between the poles m and the bar 0 is reel'fected. The bar 0 and its associated contacts constitute one form of circuit-changing means governed by the carbons for energizing and deenergizing the electromagnetic clutch member.

I have provided slots u u, preferably in angular extensions of the spool-heads, through which screws 1) /U, attached to the bar 0, project, these screws being capable of longitudinal movement in the slots as the bar 0 is elevated and lowered, the groove and engaging slots acting as guiding means.

I provide a lava or other insulating washer or collar in upon the floor of the lamp, through which washer the upper carbon passes. The upper-carbon holder 7c, when the carbons are nearly consumed, engages the washer w, the are gradually elongating until it is extinguished.

A springoc may be mounted upon the magnet Z to have contact with the bar 0 to secure more perfect electrical contact.

I have herein shown and particularly described the preferred embodiment of my invention and a particular form of lamp to which the invention has been applied; but the invention may have wide application, and I do not, therefore, wish to be limited to the character of the circuit to which the lamp is adapted, nor to the character of the current for operating the lamp, nor to the precise details of construction herein set forth; but,

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. In an arc-lamp, the con'ibination with a regulating-magnet in circuit with the carbons of the lamp, of an electromagnetic clutch member, a body of magnetizable material associated therewith, means whereby one of the carbons can be held from feeding when the magnetizable material is engaged by the clutch member, and can feed when it is disengaged therefrom, the said member having its helix adapted also for inclusion in circuit with the carbons of the lamp, said regulatingmagnet, upon partial deenergization, due to increased resistance at the arc permitting said electromagnetic clutch member, with its as sociated body of magnetizable material, to descend, and means operated upon the dcscent of said clutch mechanism for dcenergizing the said clutch member to permit feeding, the said regulating-magnet by thus having its strength increased being thereupon adapted to elevate the clutching mechanism and restore or increase the energization of the electromagnetic clutch member to reei'fect engagement between said member and the associated body of magnetizable material to cause the feeding to cease, substantially as described.

2. In an arc-lamp, the combination with an electromagnetic clutch member, of a body of magnetizable material, means whereby one of the carbons can be held from feeding when the magnetizable material is engaged by the clutch member, and can feed when it is disengaged therefrom, a regulating-magnet in circuit with the carbons of the lamp, whereby its degree of energization is varied upon a change in resistance at the are, said regulating-magnet being connected with the electromagnetic clutch member and the magnetizable material when the latter are magnetically attracted to maintain the carbons of the lamp in separated relation, and means operatively associated with the regulating magnet for deenergizing the said clutch member upon a deenergization of the regulating-mag net occurring upon an increase in resistance at the arc of the lamp to effect disengagement between the electromagnetic clutch member and its associated body of magnetiz able material, whereby the feeding carbon is released and feeding permitted to decrease the resistance at the arc, to increase the energization of the regulating-magnet, which through the agency of the last-aforesaid means thereupon serves to restore or increase the energization of the clutch member to reeffect engagement between the same and the said body. of magnetizable material to cause the feeding to cease, substantially as described.

3. In an arc-lamp, the combination with an electromagnetic clutch member movable with one of the carbons of the lamp, of a bar 0 of magnetizable material adapted for magnetic attraction bythe said clutch member, means coacting with the bar 0 for controlling the circuit through the winding of the electromagnetic clutch member, and a regulating-magnet serving through the agency of said magnetizable bar and the said clutch member when energized to maintain the carbons separated and prevent feeding, the said regulating-magnet when partially deenergized upon an increase of resistance at the are serving to operate the aforesaid means to deenergize the magnetic clutch member to release the bar 0 from its engagement with the said clutch member to permit feeding, the regulatingmagnet thereupon serving to operate the said means to restore the energization of the mag netic clutch member to reeffect engagement between the same and the said bar of magnetizable material to cause the feeding to cease, substantially as described.

4. In an arc-lamp, the combination with an electromagnetic clutch member movable with one of the carbons of the lamp, of a bar 0 of magnetizable material adapted for magnetic attraction by the said clutch member, means coacting with the bar 0 for controlling the circuit through the winding of the electromagnetic clutch member, and a regulating-magnet serving through the agency of said magnetizable bar and the said clutch member when energized to maintain the carbons separated and prevent feedi ng, the said regulatingmagnet when partially dcenergized upon an increase of resistance at the are serving to operate the aforesaid means to deenergize the magnetic clutch member to release the bar 0 from its engagement with the said clutch member to permit feeding, the regulatingmagnet thereupon serving to operate the said means to restore the energization of the magnetic clutch member to reeffect engagement between the same and the said bar of maguetizable material to cause the feeding to cease, the windings of the regulating-magnet and clutch members being included in series with the carbons, substantially as described.

5. In an arc-lamp, the combination with an electromagnetic clutch member movable with one of the carbons of the lamp, of a bar 0 of magnetizable material adapted for magnetic attraction by the said clutch member, means coacting with the bar 0 for controlling the circuit through the Winding of the electromagnetic clutch member, and a regulating-magnet serving through the agency of said magnetizable bar and the said clutch member when energized to maintain the carbons separated and prevent feeding,the said regulatingmagnet when partially deencrgized upon an increase of resistance at the are serving to 0perate the aforesaid means to deenergize the magnetic clutch member to release the bar 0 from its engagement with the said clutch member to permit feeding, the regulatingmagnet thereupon serving to operate the said means to restore the energization of the magnetic clutch member to reeffect engagement between the same and the said bar of magnetizable material to cause the feeding to cease, the windings of the regulating magnet and clutch members being included in series with the carbons and each other, substantially as described.

6. In an electric-arc lamp, the combination with an electromagnetic clutch member carried by a carbon, of a vertically-movable bar of magnetizable material 0, adapted for engagement with the clutch member, a regulating-magnet having operative connection with the bar 0 and serving through the agency of the same and the said electromagnetic clutch member when energized to maintain the carbons in a separated relation and to prevent feeding, a contact 1) placed in the path of the bar 0 and circuit connections whereby upon the descent of the bar 0 the clutch member is deenergized and feeding permitted, the regulating-magnet serving when its strength is increased upon this feeding to elevate the bar 0 and thereby restore the energization of the electromagnetic clutch member to cause the feeding to cease, substantially as described.

7. In an electric-arc lamp, the combination with an electromagnetic clutch member carried by a carbon, of a vertically-movable bar of magnetizable material 0 adapted for engagement with the clutch member, a regulatin g-magnet having operative connection with the bar 0 and serving through the agency of the same and the said electromagnetic clutch member, when energized, to maintain the carbons in a separated relation and to prevent feeding, a cont-act p placed in the path of the bar 0, a shunt-circuit about the winding of the magnetic clutch member controlled by the bar 0 and contact 13, the bar 0 upon its full descent serving to close said shunt-circuit, whereby the clutch member is denergized and feeding permitted, the regulatingmagnet serving when its strength is increased upon this feeding to elevate the bar 0 to open the shunt about the magnetic clutch member to effect reengagement between the said clutch member and the bar 0 to cause the feeding to cease, substantially as described.

8. In an arc-lamp, the combination with an electromagnetic clutch member, of a body of magnetizable material, means whereby feeding action on the part of the carbons is prevented when the clutch member is energized so as to engage the magnetizable material, and electromagneticregulating means for de energizing said electromagnetic clutch member to effect disengagement between said member and magnetizable material to permit feeding, substantially as described.

9. In an arc-lamp, the combination with an electromagnetic clutch member included in the lamp-circuit, of a body of magnetizable material, both operatively associated with the carbons of the lamp, means whereby feeding action on the part of the carbons is prevented when the clutch member is energized so as to engage the magnetizable material, and means for shortcircuiting the winding of the said clutch member to permit feeding, substantially as described.

10. In an arc-lamp, the combination with a regulating-magnet for effecting the separation of carbons, of an electromagnetic clutch member, a body of magnetizable material, the said memberand magnetizable material being operatively associated with the carbons of the lamp, means whereby feeding action on the part of the carbons is prevented when the clutch member is energized so as to engage the magnetizable material, and means controlled by said regulating-magnet for releasing the magnetic engagement between said electromagnetic clutch member and the said err-1,512-

body of magnetizable material to permit feeding, substantially as described.

11. In an arc-lamp, the combination with a regulating-magnet for effecting the separation of carbons, of an electromagnetic clutch member, a body of magnetizable material adapted to be magnetically attracted by said clutch member, means whereby feeding action on the part of the carbons is prevented when the clutchmember is energized so as to engage the magnetizable material, and means for denergizing the electromagnetic clutch member to release its associated body of magnetizable material and permit feeding, substantially as described.

12. In an arc-lamp, an electromagnetic clutch for controlling the feeding action of the carbon or carbons in combination with a circuit-changing means governed by the carbons for energizing one of the clutch members and maintaining the members of the clutch in a locked condition when the arc is normal and deenergizing the same to unlock the clutch members when the arc is too long, substantially as described.

13. In an arc-lamp,a feed-controlling clutch comprising a couple of relatively movable magnetizable members, means for energizing one of such members so as to cause it to engage the other to prevent relative movement between the two,and means whereby the feeding action is prevented when the said members are in engagement and is caused by the relative movement of the members permitted by their disengagement, substantially as described.

14:. In an arc-lamp,a feed-controlling clutch comprising a couple of relatively movable magnetizable members, one of which is provided with means for its magnetization to cause it to hold the two against relative move ment, and means whereby the feeding action can be caused to take place when the members are disengaged, and prevented when they are engaged, and means for maintaining the members in a locked condition when the arc is normal and unlocking them when the arc is too long, substantially as described.

In Witness whereof I hereunto subscribe my name this 8th day of June, A. D. 1900.

THOMAS E. DROI-IAN.

Witnesses:

GEORGE L. CRAGG, HARVEY L. HANSON. 

